Composition socket for artificial legs



May 9, 1933.

C. H. DAVIES COMPOSITION SOCKET FOR ARTIFICIAL L EGS Filed July 5, 1931lNI/ENTOR dz&; ATTORNEY WITNESS:

Patented May 9 1933 UNITED STATES" cmms 1i. navms, or rmLamiLrniA,rmmsnvanm COMPOSITION SOCKET F63 ARTIFICIAL LEGS Application filed m a,

the amputated stump and tries to duplicate this shell by carving out ofa solid block of a wood various bone projections, and also attempts toprovide, suflicient room for the irregular and tender stump. The resultsobtained depend solely upon his judgment.

The task outlined is laborious and the results are always in question.Several fittings are necessary, frequently painful to the patient. Afterseveral hours of fitting, the patient is then obliged to tell the woodsocket builder what result has been obtained, and whether or not the fitis comfortable. Obviously it is difficult if not almost impossible forthe wood socket builder. to du plicate the shell cast of the amputatedlimb with its various indentations, bone projections and irregularshape, and to construct a comfortable fitting socket to which thepatient is justly entitled.

In the construction of leather sockets, a shell plaster of paris cast istaken of the stump. This cast is then removed from'the stump and filledwith liquid plaster of paris.

After hardening, the outer shell is removed from the plaster cast,leaving the solid cast, which is a du licate of the stump of theamputated limb The bone projections-are built up according to themechanics skill. Em iricism is again evident, and the fit of t e leathersocket also depends upon the judgment of the socket builder. The leatheris saturated with water and stretched afiound the cast, and thereafterhammered around the proj actions, the hammering being done to bring outmore prominentlytindentations essential to the fit. The leather is nowdried, and in drying contracts and provides a base, and is sanitary,waterproof, and emconcentrated steam under a pressure of 30.

heated to 212 degrees -F. is applied as de- 1981. Serial-No. 548,642.

socket that fits the stump fairly well. This socket is then attached tothe shin piece of the limb and 'a second layer ofleather is built aroundthe first to reinforce it..

The disadvantages of the leather socket are its flexibility, theabsorption'of perspiration, the excessive weight, and an occa-- sionalsecretion of matter from the leather which becomes a serious irritant tothe stump. When a leather socket becomes wet, m the fit is quitenaturally afi'ected.

My invention relates to a perfect fitting composition socket forartificial limbs, which socket is absolute and positive in securing anaccurate reproduction of the cast, theref by providing a comfortable fitWithout dependingupon the skill of the operator. Empiricism-iseliminated, and the operator per orms his work in a scientific andaccu-: rate manner. A comfortable and accurate fitting socket can bebuilt by this method by the average laborer and in one-fifth of the timerequired to construct a wooden. socket, or one-third of the timerequired to construct a leather socket, and in addition eliminatesone-half of the weight and material, and is surprisingly economical. Due

to its strength, apertures or health holes may be perforated in thecomposition perfeet fitting socket, to permit air toget to the stump.Moreover, the article is extremely light, a most acceptable feature tothe limb wearer.-' r

The material used has a nitrocellulose pervious to perspiration. Due toits remarkable strength, it can be inserted into the metallic shin' orattached to a wooden shin of an artificial limb and is permitted to hangfreely as illustrated in the accomvpanying drawing.

'Shouldit become necessaryfor the bone projections already provided forin the cast, and built up by felt pads, togive more room,

pounds is applied by flexible tubular means to the exact spot whererelief is necessary. As the steam is applied to thespot, the action isthe same as when the hot water scribed below, for softening the tube.The operator presses the socket. out at this point, thereby givingsuflicient room to warrant immediate relief without cutting the materialand thereby weakening the socket.

In the drawing,

Figure 1 is in section and elevation, and shows the mold being formedon-the stump.

Figure 2 is in section and elevation and shows the mold filled withplaster of paris.

Figure 3 represents the element thus cast in elevation;

Figure 4 illustrates in perspective a composition tube to be shaped informing the socket.

Figure.5 shows a tapering mandrel in elevation, the tube after beingmoistened and heated and stretched, being .in section and surroundingthe mandrel.

Figures 6, 7, 8, partly in vertical section, show further stepsdescribed below.

Figure 9 shows the completed socket applied within the upper portion ofthe'limb.

The procedure for the construction of this composition perfect fittingsocket for the amputated limb is as follows:

In Figure 1 the projections the bone 1 are assumed to built up withsmall felt pads caused to adhere to the stump. Then a sock is drawn overthe stump, and plaster of paris is applied as shown at 2 and is builtupto one-fourth .of an inch in thickness. Figure 2 shows the mold filledwith liquid plaster of paris 3 and this is permitted to harden and con--statutes an exact duplicate of the stump in-' cluding the projections.The outer material is cut away,'leaving the element 3, in solid form. f

. vA composition tube 5 including nitrocel- .lulose as its basematerial, is shown in Figure 4. The characteristics of this material andthe advanta for using it in the building of sockets or artificial limbsare that when immersed in hot water and heated to 212-degrees F.,'itwill soften,-so that it may be stretched, and after having beenstretched it is permitted to cool. When again inserted into hotwater, itori a1 size.

igure 5 shows a 'tubenitrocellulose stretched around a tapering mandrel6. The

- end of the tube is smaller in diameter than the end of the castelement 3.- The tube 5 takei. out of the tubing, and the element 3 isinserted as-in-Figure 6. The u per end ..of the tubing has been lappedat to provide 'a shoulder to rest on the top of the at the point 12.

A. B. 'o. of

will contract to its metal shin 11. at point 12. The assembled Ielements of Figure 6 are then re-inserted into hot water and heated. to212 degrees F.

The characteristic of the material when heated a second time is toshrink back to its original size (Figure 4). The tube then becomes anexact duplicate of the cast ele-.

not shrink. Theshell 5 having the covering 8 provides a perfect fittingcomposition gnated with pyralin and socket and is then inserted into themetallic shin 11 and rests on the seat 7 Figure 9,

In most instances D in the calf of the limb. In order to se-' cure theclose fit of the socket at this point,

the atrophied stump is' smaller than the good limb.. The artificial andeliminate'all possible lost motion, vertical movement oririction,celastic is wrapped around the shell 5 as in Figure 9, tofill in thisportionof the limb. The shell is now riveted to the metal or wooden shinat point 13 and the structure is complete.

It may be observed that the essential orm the socket 5 are,: first, thatit is-hard at atmospheric temperatures; second, capable of bein renderedtemporarily soft'and self to the precise details of construction or ament or method of. procedure herein set. forth, as it' is obvious thatvarious modifications may be. made therein without de parting from theessential features of my invention, as defined in What I claimis:

1. The method of forming a socket of properties of the cellulosiccomposition to the appended claims; I

hardened plastic cellulosic material for 1511- an artificial limb, tofit the atrophied natural stump of an amputated limb; which consists 'inmaking thereb forming a matrix "conforming to the.

, conical .form of said. stump; 1e-- moving said matrixv from the. stumpand V a cast' of plastic material around said stump andthe artificialstump 'of plastic material;

rendering plastic a primarily cylindricaltube of cellulosic materialwhich is at atmospheric temperature, by heating .1t to.

thetube and form a shoulder; causing said conical tube to, harden insuch distended form; inserting the artificial stump in that hardenedtube of conical cellulosic material;

again heating said tube of cellulosicmate rial to approximately 212 F.,and allowing it to cool, shrink, and-harden upon said artificial stump,to form a socket which will fit the natural stump; removing theartificial stump from said hard cellulosic socket; fitting said socketof cellulosic material in an artificial limb of rigid material; andsecuring it in said artificial limb, so positioned that when the naturalstump is inserted therein said artificial limb is presented in properrelation with said stump to resemble the amputatedlimb.

2. The method of forming a socket of hardened plastic cellulosicmaterial for lining an artificial limb, to fit the tapered atrophiednatural stump of an amputated hmb; which consists in forming a matrixconforming to the irregular conical form of said stump; casting plasticmaterial in said matrix to form an artificial stmnp, resembling thenatural stump; rendering temporarily plastic a tube of cellulosicmaterial which is hard at atmospheric temperature; stretching said tubeto a conical. tubular form,

large enough. to receive said artificial stump;

turning down the edge of said tube at its larger end to overlap theoutside of the tube and form a shoulder; causing said conical tube toharden in such distended form; in-

serting the artificial in that hardened tube of cellulosic material;again rendering 'said tube ofcellulosic material'temporarily the wallofthe limb includes means for preventing lost motion of the socket in thelimb.

5. A socket of hardened lastic cellulosic material for an arti ciallimb, to fit the tapered atrophied naturalstump of an amputated limb;consisting of an irregular conical tube, open at both ends, with itsinner surface shapedto substantially the same configuration as the outersurface of said stump; the larger end pf said socket having an externalshoulder overhanging and resting upon the adjacent end of saidartificlal limb; said shoulder being formed by and in unitary relationwith the cellulosic material of the socket.

6. A method as in claim 1, including the step of providing the socketwith a covermg formed of fabric before inserting it in the artificiallimb; whereby, said fabric covering is interposed between said socketand the inner surface of the limb.

ture. V 7 v CHARLES H. DAVIES.

' plastic, and allowing it to shrink and harden upon said artificialstump, to. form a socket which will fit the natural stump; andsecuring-said hard socket of cellulosicma-s terial in an artificial limbof .rigid material, so positioned that when the natural stump isinserted therein said artificial limb is presented in proper relationwith said stump toresemble the amputated limb. 3. A socket of hardenedplastic'c'ellulosic material for lining an artificial limb, to. fit ithe tapered 'atropliied natural stump of an amputated limb; consistingof an irregular conical tube, "open at both ends, with its inner surfaceshaped to substantially the same configuration as the outer surface ofsaid stump; the larger end of said socket shaped to fit, incontact-with, the wall of said limb, and means for holding the smiilllerend of said socket spaced from said Wa means for holding said socketspaced from In testimony whereof I afiix my signa-

